A new technology will be developed for long term neural recordings using intra-cortical microelectrode arrays. One important desired feature of long-term neural recordings is the ability to record from the same neurons from month to month or year to year. However, with existing technology this is very difficult to accomplish. One possible reason may be motion of the microelectrode array relative to the neural tissue caused by wiring from the arrays to the skull. A small, lightweight, wireless neural recording telemeter embedded in the pia so it could move with the brain may exhibit improved capacity for reproducibly recording from single units for long times. The objective of the proposed work is to develop and evaluate a tetherless, small, lightweight 16-channel telemeter. This telemeter will be attached directly to intra-cortical microelectrode arrays for placement on the pia. The packaging will be of the appropriate materials and shape to encourage encapsulation and stabilization by the pia. Data and power will be telemetered through the skull to external instrumentation. Rabbit, dog, cat and monkey will be used as animal models in this study to evaluate the technology in a variety of circumstances and with a variety of existing protocols. Metrics of the technology include: long term assessment of the electrical properties of the system; length of time that single units can be maintained; amplitude stability of single units over time; neuron density about the microelectrodes; degree of encapsulation by the pia; migration distance of the microelectrodes; and evidence of micro-hemorrhages. The primary application of this technology will be to facilitate long term intra-cortical chronic recordings for neuroscience. Perhaps when the technology is fully developed, it will be possible to apply it to rehabilitation of the spinal cord injured. An example would be for extraction of motor control information for control of functional electrical stimulation systems.